buildkit/util/throttle/throttle.go

59 lines
1.0 KiB
Go

package throttle
import (
"sync"
"time"
)
// Throttle wraps a function so that internal function does not get called
// more frequently than the specified duration.
func Throttle(d time.Duration, f func()) func() {
return throttle(d, f, true)
}
// After wraps a function so that internal function does not get called
// more frequently than the specified duration. The delay is added after function
// has been called.
func After(d time.Duration, f func()) func() {
return throttle(d, f, false)
}
func throttle(d time.Duration, f func(), wait bool) func() {
var next, running bool
var mu sync.Mutex
return func() {
mu.Lock()
defer mu.Unlock()
next = true
if !running {
running = true
go func() {
for {
mu.Lock()
if next == false {
running = false
mu.Unlock()
return
}
if !wait {
next = false
}
mu.Unlock()
if wait {
time.Sleep(d)
mu.Lock()
next = false
mu.Unlock()
f()
} else {
f()
time.Sleep(d)
}
}
}()
}
}
}